/***************************************************************************/
/*                                                                         */
/*  ttgxvar.c                                                              */
/*                                                                         */
/*    TrueType GX Font Variation loader                                    */
/*                                                                         */
/*  Copyright 2004, 2005, 2006, 2007, 2008, 2009 by                        */
/*  David Turner, Robert Wilhelm, Werner Lemberg, and George Williams.     */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used,       */
/*  modified, and distributed under the terms of the FreeType project      */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/


/*************************************************************************/
/*                                                                       */
/* Apple documents the `fvar', `gvar', `cvar', and `avar' tables at      */
/*                                                                       */
/*   http://developer.apple.com/fonts/TTRefMan/RM06/Chap6[fgca]var.html  */
/*                                                                       */
/* The documentation for `fvar' is inconsistent.  At one point it says   */
/* that `countSizePairs' should be 3, at another point 2.  It should     */
/* be 2.                                                                 */
/*                                                                       */
/* The documentation for `gvar' is not intelligible; `cvar' refers you   */
/* to `gvar' and is thus also incomprehensible.                          */
/*                                                                       */
/* The documentation for `avar' appears correct, but Apple has no fonts  */
/* with an `avar' table, so it is hard to test.                          */
/*                                                                       */
/* Many thanks to John Jenkins (at Apple) in figuring this out.          */
/*                                                                       */
/*                                                                       */
/* Apple's `kern' table has some references to tuple indices, but as     */
/* there is no indication where these indices are defined, nor how to    */
/* interpolate the kerning values (different tuples have different       */
/* classes) this issue is ignored.                                       */
/*                                                                       */
/*************************************************************************/


#include <ft2build.h>
#include FT_INTERNAL_DEBUG_H
#include FT_CONFIG_CONFIG_H
#include FT_INTERNAL_STREAM_H
#include FT_INTERNAL_SFNT_H
#include FT_TRUETYPE_TAGS_H
#include FT_MULTIPLE_MASTERS_H

#include "ttpload.h"
#include "ttgxvar.h"

#include "tterrors.h"


#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT


    #define FT_Stream_FTell(stream) \
    ((stream)->cursor - (stream)->base)
    #define FT_Stream_SeekSet(stream, off) \
    ((stream)->cursor = (stream)->base + (off))


/*************************************************************************/
/*                                                                       */
/* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
/* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
/* messages during execution.                                            */
/*                                                                       */
    #undef  FT_COMPONENT
    #define FT_COMPONENT trace_ttgxvar


/*************************************************************************/
/*************************************************************************/
/*****                                                               *****/
/*****                       Internal Routines                       *****/
/*****                                                               *****/
/*************************************************************************/
/*************************************************************************/


/*************************************************************************/
/*                                                                       */
/* The macro ALL_POINTS is used in `ft_var_readpackedpoints'.  It        */
/* indicates that there is a delta for every point without needing to    */
/* enumerate all of them.                                                */
/*                                                                       */
    #define ALL_POINTS (FT_UShort*)(-1)


    #define GX_PT_POINTS_ARE_WORDS 0x80
    #define GX_PT_POINT_RUN_COUNT_MASK 0x7F


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    ft_var_readpackedpoints                                            */
/*                                                                       */
/* <Description>                                                         */
/*    Read a set of points to which the following deltas will apply.     */
/*    Points are packed with a run length encoding.                      */
/*                                                                       */
/* <Input>                                                               */
/*    stream    :: The data stream.                                      */
/*                                                                       */
/* <Output>                                                              */
/*    point_cnt :: The number of points read.  A zero value means that   */
/*                 all points in the glyph will be affected, without     */
/*                 enumerating them individually.                        */
/*                                                                       */
/* <Return>                                                              */
/*    An array of FT_UShort containing the affected points or the        */
/*    special value ALL_POINTS.                                          */
/*                                                                       */
static FT_UShort*
ft_var_readpackedpoints(FT_Stream stream,
                        FT_UInt* point_cnt)
{
    FT_UShort* points;
    FT_Int n;
    FT_Int runcnt;
    FT_Int i;
    FT_Int j;
    FT_Int first;
    FT_Memory memory = stream->memory;
    FT_Error error = TT_Err_Ok;

    FT_UNUSED(error);


    *point_cnt = n = FT_GET_BYTE();
    if (n == 0)
        return ALL_POINTS;

    if (n & GX_PT_POINTS_ARE_WORDS)
        n = FT_GET_BYTE() | ((n & GX_PT_POINT_RUN_COUNT_MASK) << 8);

    if (FT_NEW_ARRAY(points, n))
        return NULL;

    i = 0;
    while (i < n)
    {
        runcnt = FT_GET_BYTE();
        if (runcnt & GX_PT_POINTS_ARE_WORDS)
        {
            runcnt = runcnt & GX_PT_POINT_RUN_COUNT_MASK;
            first = points[i++] = FT_GET_USHORT();

            if (runcnt < 1)
                goto Exit;

            /* first point not included in runcount */
            for (j = 0; j < runcnt; ++j)
                points[i++] = (FT_UShort)(first += FT_GET_USHORT());
        }
        else
        {
            first = points[i++] = FT_GET_BYTE();

            if (runcnt < 1)
                goto Exit;

            for (j = 0; j < runcnt; ++j)
                points[i++] = (FT_UShort)(first += FT_GET_BYTE());
        }
    }

Exit:
    return points;
}


enum
{
    GX_DT_DELTAS_ARE_ZERO = 0x80,
    GX_DT_DELTAS_ARE_WORDS = 0x40,
    GX_DT_DELTA_RUN_COUNT_MASK = 0x3F
};


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    ft_var_readpackeddeltas                                            */
/*                                                                       */
/* <Description>                                                         */
/*    Read a set of deltas.  These are packed slightly differently than  */
/*    points.  In particular there is no overall count.                  */
/*                                                                       */
/* <Input>                                                               */
/*    stream    :: The data stream.                                      */
/*                                                                       */
/*    delta_cnt :: The number of to be read.                             */
/*                                                                       */
/* <Return>                                                              */
/*    An array of FT_Short containing the deltas for the affected        */
/*    points.  (This only gets the deltas for one dimension.  It will    */
/*    generally be called twice, once for x, once for y.  When used in   */
/*    cvt table, it will only be called once.)                           */
/*                                                                       */
static FT_Short*
ft_var_readpackeddeltas(FT_Stream stream,
                        FT_Offset delta_cnt)
{
    FT_Short* deltas;
    FT_UInt runcnt;
    FT_Offset i;
    FT_UInt j;
    FT_Memory memory = stream->memory;
    FT_Error error = TT_Err_Ok;

    FT_UNUSED(error);


    if (FT_NEW_ARRAY(deltas, delta_cnt))
        return NULL;

    i = 0;
    while (i < delta_cnt)
    {
        runcnt = FT_GET_BYTE();
        if (runcnt & GX_DT_DELTAS_ARE_ZERO)
        {
            /* runcnt zeroes get added */
            for (j = 0;
                 j <= (runcnt & GX_DT_DELTA_RUN_COUNT_MASK) && i < delta_cnt;
                 ++j)
                deltas[i++] = 0;
        }
        else if (runcnt & GX_DT_DELTAS_ARE_WORDS)
        {
            /* runcnt shorts from the stack */
            for (j = 0;
                 j <= (runcnt & GX_DT_DELTA_RUN_COUNT_MASK) && i < delta_cnt;
                 ++j)
                deltas[i++] = FT_GET_SHORT();
        }
        else
        {
            /* runcnt signed bytes from the stack */
            for (j = 0;
                 j <= (runcnt & GX_DT_DELTA_RUN_COUNT_MASK) && i < delta_cnt;
                 ++j)
                deltas[i++] = FT_GET_CHAR();
        }

        if (j <= (runcnt & GX_DT_DELTA_RUN_COUNT_MASK))
        {
            /* Bad format */
            FT_FREE(deltas);
            return NULL;
        }
    }

    return deltas;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    ft_var_load_avar                                                   */
/*                                                                       */
/* <Description>                                                         */
/*    Parse the `avar' table if present.  It need not be, so we return   */
/*    nothing.                                                           */
/*                                                                       */
/* <InOut>                                                               */
/*    face :: The font face.                                             */
/*                                                                       */
static void
ft_var_load_avar(TT_Face face)
{
    FT_Stream stream = FT_FACE_STREAM(face);
    FT_Memory memory = stream->memory;
    GX_Blend blend = face->blend;
    GX_AVarSegment segment;
    FT_Error error = TT_Err_Ok;
    FT_ULong version;
    FT_Long axisCount;
    FT_Int i, j;
    FT_ULong table_len;

    FT_UNUSED(error);


    blend->avar_checked = TRUE;
    if ((error = face->goto_table(face, TTAG_avar, stream, &table_len)) != 0)
        return;

    if (FT_FRAME_ENTER(table_len))
        return;

    version = FT_GET_LONG();
    axisCount = FT_GET_LONG();

    if (version != 0x00010000L ||
        axisCount != (FT_Long)blend->mmvar->num_axis)
        goto Exit;

    if (FT_NEW_ARRAY(blend->avar_segment, axisCount))
        goto Exit;

    segment = &blend->avar_segment[0];
    for (i = 0; i < axisCount; ++i, ++segment)
    {
        segment->pairCount = FT_GET_USHORT();
        if (FT_NEW_ARRAY(segment->correspondence, segment->pairCount))
        {
            /* Failure.  Free everything we have done so far.  We must do */
            /* it right now since loading the `avar' table is optional.   */

            for (j = i - 1; j >= 0; --j)
                FT_FREE(blend->avar_segment[j].correspondence);

            FT_FREE(blend->avar_segment);
            blend->avar_segment = NULL;
            goto Exit;
        }

        for (j = 0; j < segment->pairCount; ++j)
        {
            segment->correspondence[j].fromCoord =
                FT_GET_SHORT() << 2; /* convert to Fixed */
            segment->correspondence[j].toCoord =
                FT_GET_SHORT() << 2; /* convert to Fixed */
        }
    }

Exit:
    FT_FRAME_EXIT();
}


typedef struct  GX_GVar_Head_
{
    FT_Long version;
    FT_UShort axisCount;
    FT_UShort globalCoordCount;
    FT_ULong offsetToCoord;
    FT_UShort glyphCount;
    FT_UShort flags;
    FT_ULong offsetToData;

} GX_GVar_Head;


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    ft_var_load_gvar                                                   */
/*                                                                       */
/* <Description>                                                         */
/*    Parses the `gvar' table if present.  If `fvar' is there, `gvar'    */
/*    had better be there too.                                           */
/*                                                                       */
/* <InOut>                                                               */
/*    face :: The font face.                                             */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
static FT_Error
ft_var_load_gvar(TT_Face face)
{
    FT_Stream stream = FT_FACE_STREAM(face);
    FT_Memory memory = stream->memory;
    GX_Blend blend = face->blend;
    FT_Error error;
    FT_UInt i, j;
    FT_ULong table_len;
    FT_ULong gvar_start;
    FT_ULong offsetToData;
    GX_GVar_Head gvar_head;

    static const FT_Frame_Field gvar_fields[] =
    {

        #undef  FT_STRUCTURE
    #define FT_STRUCTURE GX_GVar_Head

        FT_FRAME_START(20),
        FT_FRAME_LONG(version),
        FT_FRAME_USHORT(axisCount),
        FT_FRAME_USHORT(globalCoordCount),
        FT_FRAME_ULONG(offsetToCoord),
        FT_FRAME_USHORT(glyphCount),
        FT_FRAME_USHORT(flags),
        FT_FRAME_ULONG(offsetToData),
        FT_FRAME_END
    };

    if ((error = face->goto_table(face, TTAG_gvar, stream, &table_len)) != 0)
        goto Exit;

    gvar_start = FT_STREAM_POS();
    if (FT_STREAM_READ_FIELDS(gvar_fields, &gvar_head))
        goto Exit;

    blend->tuplecount = gvar_head.globalCoordCount;
    blend->gv_glyphcnt = gvar_head.glyphCount;
    offsetToData = gvar_start + gvar_head.offsetToData;

    if (gvar_head.version != (FT_Long)0x00010000L ||
        gvar_head.axisCount != (FT_UShort)blend->mmvar->num_axis)
    {
        error = TT_Err_Invalid_Table;
        goto Exit;
    }

    if (FT_NEW_ARRAY(blend->glyphoffsets, blend->gv_glyphcnt + 1))
        goto Exit;

    if (gvar_head.flags & 1)
    {
        /* long offsets (one more offset than glyphs, to mark size of last) */
        if (FT_FRAME_ENTER((blend->gv_glyphcnt + 1) * 4L))
            goto Exit;

        for (i = 0; i <= blend->gv_glyphcnt; ++i)
            blend->glyphoffsets[i] = offsetToData + FT_GET_LONG();

        FT_FRAME_EXIT();
    }
    else
    {
        /* short offsets (one more offset than glyphs, to mark size of last) */
        if (FT_FRAME_ENTER((blend->gv_glyphcnt + 1) * 2L))
            goto Exit;

        for (i = 0; i <= blend->gv_glyphcnt; ++i)
            blend->glyphoffsets[i] = offsetToData + FT_GET_USHORT() * 2;
        /* XXX: Undocumented: `*2'! */

        FT_FRAME_EXIT();
    }

    if (blend->tuplecount != 0)
    {
        if (FT_NEW_ARRAY(blend->tuplecoords,
                         gvar_head.axisCount * blend->tuplecount))
            goto Exit;

        if (FT_STREAM_SEEK(gvar_start + gvar_head.offsetToCoord) ||
            FT_FRAME_ENTER(blend->tuplecount * gvar_head.axisCount * 2L))
            goto Exit;

        for (i = 0; i < blend->tuplecount; ++i)
            for (j = 0; j < (FT_UInt)gvar_head.axisCount; ++j)
                blend->tuplecoords[i * gvar_head.axisCount + j] =
                    FT_GET_SHORT() << 2;        /* convert to FT_Fixed */

        FT_FRAME_EXIT();
    }

Exit:
    return error;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    ft_var_apply_tuple                                                 */
/*                                                                       */
/* <Description>                                                         */
/*    Figure out whether a given tuple (design) applies to the current   */
/*    blend, and if so, what is the scaling factor.                      */
/*                                                                       */
/* <Input>                                                               */
/*    blend           :: The current blend of the font.                  */
/*                                                                       */
/*    tupleIndex      :: A flag saying whether this is an intermediate   */
/*                       tuple or not.                                   */
/*                                                                       */
/*    tuple_coords    :: The coordinates of the tuple in normalized axis */
/*                       units.                                          */
/*                                                                       */
/*    im_start_coords :: The initial coordinates where this tuple starts */
/*                       to apply (for intermediate coordinates).        */
/*                                                                       */
/*    im_end_coords   :: The final coordinates after which this tuple no */
/*                       longer applies (for intermediate coordinates).  */
/*                                                                       */
/* <Return>                                                              */
/*    An FT_Fixed value containing the scaling factor.                   */
/*                                                                       */
static FT_Fixed
ft_var_apply_tuple(GX_Blend blend,
                   FT_UShort tupleIndex,
                   FT_Fixed* tuple_coords,
                   FT_Fixed* im_start_coords,
                   FT_Fixed* im_end_coords)
{
    FT_UInt i;
    FT_Fixed apply;
    FT_Fixed temp;


    apply = 0x10000L;
    for (i = 0; i < blend->num_axis; ++i)
    {
        if (tuple_coords[i] == 0)
            /* It's not clear why (for intermediate tuples) we don't need     */
            /* to check against start/end -- the documentation says we don't. */
            /* Similarly, it's unclear why we don't need to scale along the   */
            /* axis.                                                          */
            continue;

        else if (blend->normalizedcoords[i] == 0 ||
                 (blend->normalizedcoords[i] < 0 && tuple_coords[i] > 0) ||
                 (blend->normalizedcoords[i] > 0 && tuple_coords[i] < 0))
        {
            apply = 0;
            break;
        }

        else if (!(tupleIndex & GX_TI_INTERMEDIATE_TUPLE))
            /* not an intermediate tuple */
            apply = FT_MulDiv(apply,
                              blend->normalizedcoords[i] > 0
                              ? blend->normalizedcoords[i]
                              : -blend->normalizedcoords[i],
                              0x10000L);

        else if (blend->normalizedcoords[i] <= im_start_coords[i] ||
                 blend->normalizedcoords[i] >= im_end_coords[i])
        {
            apply = 0;
            break;
        }

        else if (blend->normalizedcoords[i] < tuple_coords[i])
        {
            temp = FT_MulDiv(blend->normalizedcoords[i] - im_start_coords[i],
                             0x10000L,
                             tuple_coords[i] - im_start_coords[i]);
            apply = FT_MulDiv(apply, temp, 0x10000L);
        }

        else
        {
            temp = FT_MulDiv(im_end_coords[i] - blend->normalizedcoords[i],
                             0x10000L,
                             im_end_coords[i] - tuple_coords[i]);
            apply = FT_MulDiv(apply, temp, 0x10000L);
        }
    }

    return apply;
}


/*************************************************************************/
/*************************************************************************/
/*****                                                               *****/
/*****               MULTIPLE MASTERS SERVICE FUNCTIONS              *****/
/*****                                                               *****/
/*************************************************************************/
/*************************************************************************/


typedef struct  GX_FVar_Head_
{
    FT_Long version;
    FT_UShort offsetToData;
    FT_UShort countSizePairs;
    FT_UShort axisCount;
    FT_UShort axisSize;
    FT_UShort instanceCount;
    FT_UShort instanceSize;

} GX_FVar_Head;


typedef struct  fvar_axis_
{
    FT_ULong axisTag;
    FT_ULong minValue;
    FT_ULong defaultValue;
    FT_ULong maxValue;
    FT_UShort flags;
    FT_UShort nameID;

} GX_FVar_Axis;


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    TT_Get_MM_Var                                                      */
/*                                                                       */
/* <Description>                                                         */
/*    Check that the font's `fvar' table is valid, parse it, and return  */
/*    those data.                                                        */
/*                                                                       */
/* <InOut>                                                               */
/*    face   :: The font face.                                           */
/*              TT_Get_MM_Var initializes the blend structure.           */
/*                                                                       */
/* <Output>                                                              */
/*    master :: The `fvar' data (must be freed by caller).               */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
FT_LOCAL_DEF(FT_Error)
TT_Get_MM_Var(TT_Face face,
              FT_MM_Var * *master)
{
    FT_Stream stream = face->root.stream;
    FT_Memory memory = face->root.memory;
    FT_ULong table_len;
    FT_Error error = TT_Err_Ok;
    FT_ULong fvar_start;
    FT_Int i, j;
    FT_MM_Var* mmvar;
    FT_Fixed* next_coords;
    FT_String* next_name;
    FT_Var_Axis* a;
    FT_Var_Named_Style* ns;
    GX_FVar_Head fvar_head;

    static const FT_Frame_Field fvar_fields[] =
    {

        #undef  FT_STRUCTURE
    #define FT_STRUCTURE GX_FVar_Head

        FT_FRAME_START(16),
        FT_FRAME_LONG(version),
        FT_FRAME_USHORT(offsetToData),
        FT_FRAME_USHORT(countSizePairs),
        FT_FRAME_USHORT(axisCount),
        FT_FRAME_USHORT(axisSize),
        FT_FRAME_USHORT(instanceCount),
        FT_FRAME_USHORT(instanceSize),
        FT_FRAME_END
    };

    static const FT_Frame_Field fvaraxis_fields[] =
    {

        #undef  FT_STRUCTURE
    #define FT_STRUCTURE GX_FVar_Axis

        FT_FRAME_START(20),
        FT_FRAME_ULONG(axisTag),
        FT_FRAME_ULONG(minValue),
        FT_FRAME_ULONG(defaultValue),
        FT_FRAME_ULONG(maxValue),
        FT_FRAME_USHORT(flags),
        FT_FRAME_USHORT(nameID),
        FT_FRAME_END
    };


    if (face->blend == NULL)
    {
        /* both `fvar' and `gvar' must be present */
        if ((error = face->goto_table(face, TTAG_gvar,
                                      stream, &table_len)) != 0)
            goto Exit;

        if ((error = face->goto_table(face, TTAG_fvar,
                                      stream, &table_len)) != 0)
            goto Exit;

        fvar_start = FT_STREAM_POS();

        if (FT_STREAM_READ_FIELDS(fvar_fields, &fvar_head))
            goto Exit;

        if (fvar_head.version != (FT_Long)0x00010000L ||
            fvar_head.countSizePairs != 2 ||
            fvar_head.axisSize != 20 ||
            fvar_head.instanceSize != 4 + 4 * fvar_head.axisCount ||
            fvar_head.offsetToData + fvar_head.axisCount * 20U +
            fvar_head.instanceCount * fvar_head.instanceSize > table_len)
        {
            error = TT_Err_Invalid_Table;
            goto Exit;
        }

        if (FT_NEW(face->blend))
            goto Exit;

        /* XXX: TODO - check for overflows */
        face->blend->mmvar_len =
            sizeof(FT_MM_Var) +
            fvar_head.axisCount * sizeof(FT_Var_Axis) +
            fvar_head.instanceCount * sizeof(FT_Var_Named_Style) +
            fvar_head.instanceCount * fvar_head.axisCount * sizeof(FT_Fixed) +
            5 * fvar_head.axisCount;

        if (FT_ALLOC(mmvar, face->blend->mmvar_len))
            goto Exit;
        face->blend->mmvar = mmvar;

        mmvar->num_axis =
            fvar_head.axisCount;
        mmvar->num_designs =
            (FT_UInt) - 1;     /* meaningless in this context; each glyph */
                               /* may have a different number of designs  */
                               /* (or tuples, as called by Apple)         */
        mmvar->num_namedstyles =
            fvar_head.instanceCount;
        mmvar->axis =
            (FT_Var_Axis*)&(mmvar[1]);
        mmvar->namedstyle =
            (FT_Var_Named_Style*)&(mmvar->axis[fvar_head.axisCount]);

        next_coords =
            (FT_Fixed*)&(mmvar->namedstyle[fvar_head.instanceCount]);
        for (i = 0; i < fvar_head.instanceCount; ++i)
        {
            mmvar->namedstyle[i].coords = next_coords;
            next_coords += fvar_head.axisCount;
        }

        next_name = (FT_String*)next_coords;
        for (i = 0; i < fvar_head.axisCount; ++i)
        {
            mmvar->axis[i].name = next_name;
            next_name += 5;
        }

        if (FT_STREAM_SEEK(fvar_start + fvar_head.offsetToData))
            goto Exit;

        a = mmvar->axis;
        for (i = 0; i < fvar_head.axisCount; ++i)
        {
            GX_FVar_Axis axis_rec;


            if (FT_STREAM_READ_FIELDS(fvaraxis_fields, &axis_rec))
                goto Exit;
            a->tag = axis_rec.axisTag;
            a->minimum = axis_rec.minValue; /* A Fixed */
            a->def = axis_rec.defaultValue; /* A Fixed */
            a->maximum = axis_rec.maxValue; /* A Fixed */
            a->strid = axis_rec.nameID;

            a->name[0] = (FT_String)(a->tag >> 24);
            a->name[1] = (FT_String)((a->tag >> 16) & 0xFF);
            a->name[2] = (FT_String)((a->tag >> 8) & 0xFF);
            a->name[3] = (FT_String)((a->tag) & 0xFF);
            a->name[4] = 0;

            ++a;
        }

        ns = mmvar->namedstyle;
        for (i = 0; i < fvar_head.instanceCount; ++i, ++ns)
        {
            if (FT_FRAME_ENTER(4L + 4L * fvar_head.axisCount))
                goto Exit;

            ns->strid = FT_GET_USHORT();
            (void)/* flags = */ FT_GET_USHORT();

            for (j = 0; j < fvar_head.axisCount; ++j)
                ns->coords[j] = FT_GET_ULONG(); /* A Fixed */

            FT_FRAME_EXIT();
        }
    }

    if (master != NULL)
    {
        FT_UInt n;


        if (FT_ALLOC(mmvar, face->blend->mmvar_len))
            goto Exit;
        FT_MEM_COPY(mmvar, face->blend->mmvar, face->blend->mmvar_len);

        mmvar->axis =
            (FT_Var_Axis*)&(mmvar[1]);
        mmvar->namedstyle =
            (FT_Var_Named_Style*)&(mmvar->axis[mmvar->num_axis]);
        next_coords =
            (FT_Fixed*)&(mmvar->namedstyle[mmvar->num_namedstyles]);

        for (n = 0; n < mmvar->num_namedstyles; ++n)
        {
            mmvar->namedstyle[n].coords = next_coords;
            next_coords += mmvar->num_axis;
        }

        a = mmvar->axis;
        next_name = (FT_String*)next_coords;
        for (n = 0; n < mmvar->num_axis; ++n)
        {
            a->name = next_name;

            /* standard PostScript names for some standard apple tags */
            if (a->tag == TTAG_wght)
                a->name = (char*)"Weight";
            else if (a->tag == TTAG_wdth)
                a->name = (char*)"Width";
            else if (a->tag == TTAG_opsz)
                a->name = (char*)"OpticalSize";
            else if (a->tag == TTAG_slnt)
                a->name = (char*)"Slant";

            next_name += 5;
            ++a;
        }

        *master = mmvar;
    }

Exit:
    return error;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    TT_Set_MM_Blend                                                    */
/*                                                                       */
/* <Description>                                                         */
/*    Set the blend (normalized) coordinates for this instance of the    */
/*    font.  Check that the `gvar' table is reasonable and does some     */
/*    initial preparation.                                               */
/*                                                                       */
/* <InOut>                                                               */
/*    face       :: The font.                                            */
/*                  Initialize the blend structure with `gvar' data.     */
/*                                                                       */
/* <Input>                                                               */
/*    num_coords :: Must be the axis count of the font.                  */
/*                                                                       */
/*    coords     :: An array of num_coords, each between [-1,1].         */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
FT_LOCAL_DEF(FT_Error)
TT_Set_MM_Blend(TT_Face face,
                FT_UInt num_coords,
                FT_Fixed * coords)
{
    FT_Error error = TT_Err_Ok;
    GX_Blend blend;
    FT_MM_Var* mmvar;
    FT_UInt i;
    FT_Memory memory = face->root.memory;

    enum
    {
        mcvt_retain,
        mcvt_modify,
        mcvt_load

    } manageCvt;


    face->doblend = FALSE;

    if (face->blend == NULL)
    {
        if ((error = TT_Get_MM_Var(face, NULL)) != 0)
            goto Exit;
    }

    blend = face->blend;
    mmvar = blend->mmvar;

    if (num_coords != mmvar->num_axis)
    {
        error = TT_Err_Invalid_Argument;
        goto Exit;
    }

    for (i = 0; i < num_coords; ++i)
        if (coords[i] < -0x00010000L || coords[i] > 0x00010000L)
        {
            error = TT_Err_Invalid_Argument;
            goto Exit;
        }

    if (blend->glyphoffsets == NULL)
        if ((error = ft_var_load_gvar(face)) != 0)
            goto Exit;

    if (blend->normalizedcoords == NULL)
    {
        if (FT_NEW_ARRAY(blend->normalizedcoords, num_coords))
            goto Exit;

        manageCvt = mcvt_modify;

        /* If we have not set the blend coordinates before this, then the  */
        /* cvt table will still be what we read from the `cvt ' table and  */
        /* we don't need to reload it.  We may need to change it though... */
    }
    else
    {
        manageCvt = mcvt_retain;
        for (i = 0; i < num_coords; ++i)
        {
            if (blend->normalizedcoords[i] != coords[i])
            {
                manageCvt = mcvt_load;
                break;
            }
        }

        /* If we don't change the blend coords then we don't need to do  */
        /* anything to the cvt table.  It will be correct.  Otherwise we */
        /* no longer have the original cvt (it was modified when we set  */
        /* the blend last time), so we must reload and then modify it.   */
    }

    blend->num_axis = num_coords;
    FT_MEM_COPY(blend->normalizedcoords,
                coords,
                num_coords * sizeof(FT_Fixed));

    face->doblend = TRUE;

    if (face->cvt != NULL)
    {
        switch (manageCvt)
        {
            case mcvt_load:
                /* The cvt table has been loaded already; every time we change the */
                /* blend we may need to reload and remodify the cvt table.         */
                FT_FREE(face->cvt);
                face->cvt = NULL;

                tt_face_load_cvt(face, face->root.stream);
                break;

            case mcvt_modify:
                /* The original cvt table is in memory.  All we need to do is */
                /* apply the `cvar' table (if any).                           */
                tt_face_vary_cvt(face, face->root.stream);
                break;

            case mcvt_retain:
                /* The cvt table is correct for this set of coordinates. */
                break;
        }
    }

Exit:
    return error;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    TT_Set_Var_Design                                                  */
/*                                                                       */
/* <Description>                                                         */
/*    Set the coordinates for the instance, measured in the user         */
/*    coordinate system.  Parse the `avar' table (if present) to convert */
/*    from user to normalized coordinates.                               */
/*                                                                       */
/* <InOut>                                                               */
/*    face       :: The font face.                                       */
/*                  Initialize the blend struct with `gvar' data.        */
/*                                                                       */
/* <Input>                                                               */
/*    num_coords :: This must be the axis count of the font.             */
/*                                                                       */
/*    coords     :: A coordinate array with `num_coords' elements.       */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
FT_LOCAL_DEF(FT_Error)
TT_Set_Var_Design(TT_Face face,
                  FT_UInt num_coords,
                  FT_Fixed * coords)
{
    FT_Error error = TT_Err_Ok;
    FT_Fixed* normalized = NULL;
    GX_Blend blend;
    FT_MM_Var* mmvar;
    FT_UInt i, j;
    FT_Var_Axis* a;
    GX_AVarSegment av;
    FT_Memory memory = face->root.memory;


    if (face->blend == NULL)
    {
        if ((error = TT_Get_MM_Var(face, NULL)) != 0)
            goto Exit;
    }

    blend = face->blend;
    mmvar = blend->mmvar;

    if (num_coords != mmvar->num_axis)
    {
        error = TT_Err_Invalid_Argument;
        goto Exit;
    }

    /* Axis normalization is a two stage process.  First we normalize */
    /* based on the [min,def,max] values for the axis to be [-1,0,1]. */
    /* Then, if there's an `avar' table, we renormalize this range.   */

    if (FT_NEW_ARRAY(normalized, mmvar->num_axis))
        goto Exit;

    a = mmvar->axis;
    for (i = 0; i < mmvar->num_axis; ++i, ++a)
    {
        if (coords[i] > a->maximum || coords[i] < a->minimum)
        {
            error = TT_Err_Invalid_Argument;
            goto Exit;
        }

        if (coords[i] < a->def)
        {
            normalized[i] = -FT_MulDiv(coords[i] - a->def,
                                       0x10000L,
                                       a->minimum - a->def);
        }
        else if (a->maximum == a->def)
            normalized[i] = 0;
        else
        {
            normalized[i] = FT_MulDiv(coords[i] - a->def,
                                      0x10000L,
                                      a->maximum - a->def);
        }
    }

    if (!blend->avar_checked)
        ft_var_load_avar(face);

    if (blend->avar_segment != NULL)
    {
        av = blend->avar_segment;
        for (i = 0; i < mmvar->num_axis; ++i, ++av)
        {
            for (j = 1; j < (FT_UInt)av->pairCount; ++j)
                if (normalized[i] < av->correspondence[j].fromCoord)
                {
                    normalized[i] =
                        FT_MulDiv(
                            FT_MulDiv(
                                normalized[i] - av->correspondence[j - 1].fromCoord,
                                0x10000L,
                                av->correspondence[j].fromCoord -
                                av->correspondence[j - 1].fromCoord),
                            av->correspondence[j].toCoord -
                            av->correspondence[j - 1].toCoord,
                            0x10000L) +
                        av->correspondence[j - 1].toCoord;
                    break;
                }
        }
    }

    error = TT_Set_MM_Blend(face, num_coords, normalized);

Exit:
    FT_FREE(normalized);
    return error;
}


/*************************************************************************/
/*************************************************************************/
/*****                                                               *****/
/*****                     GX VAR PARSING ROUTINES                   *****/
/*****                                                               *****/
/*************************************************************************/
/*************************************************************************/


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_face_vary_cvt                                                   */
/*                                                                       */
/* <Description>                                                         */
/*    Modify the loaded cvt table according to the `cvar' table and the  */
/*    font's blend.                                                      */
/*                                                                       */
/* <InOut>                                                               */
/*    face   :: A handle to the target face object.                      */
/*                                                                       */
/* <Input>                                                               */
/*    stream :: A handle to the input stream.                            */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
/*    Most errors are ignored.  It is perfectly valid not to have a      */
/*    `cvar' table even if there is a `gvar' and `fvar' table.           */
/*                                                                       */
FT_LOCAL_DEF(FT_Error)
tt_face_vary_cvt(TT_Face face,
                 FT_Stream stream)
{
    FT_Error error;
    FT_Memory memory = stream->memory;
    FT_ULong table_start;
    FT_ULong table_len;
    FT_UInt tupleCount;
    FT_ULong offsetToData;
    FT_ULong here;
    FT_UInt i, j;
    FT_Fixed* tuple_coords = NULL;
    FT_Fixed* im_start_coords = NULL;
    FT_Fixed* im_end_coords = NULL;
    GX_Blend blend = face->blend;
    FT_UInt point_count;
    FT_UShort* localpoints;
    FT_Short* deltas;


    FT_TRACE2(("CVAR "));

    if (blend == NULL)
    {
        FT_TRACE2(("tt_face_vary_cvt: no blend specified\n"));

        error = TT_Err_Ok;
        goto Exit;
    }

    if (face->cvt == NULL)
    {
        FT_TRACE2(("tt_face_vary_cvt: no `cvt ' table\n"));

        error = TT_Err_Ok;
        goto Exit;
    }

    error = face->goto_table(face, TTAG_cvar, stream, &table_len);
    if (error)
    {
        FT_TRACE2(("is missing\n"));

        error = TT_Err_Ok;
        goto Exit;
    }

    if (FT_FRAME_ENTER(table_len))
    {
        error = TT_Err_Ok;
        goto Exit;
    }

    table_start = FT_Stream_FTell(stream);
    if (FT_GET_LONG() != 0x00010000L)
    {
        FT_TRACE2(("bad table version\n"));

        error = TT_Err_Ok;
        goto FExit;
    }

    if (FT_NEW_ARRAY(tuple_coords, blend->num_axis) ||
        FT_NEW_ARRAY(im_start_coords, blend->num_axis) ||
        FT_NEW_ARRAY(im_end_coords, blend->num_axis))
        goto FExit;

    tupleCount = FT_GET_USHORT();
    offsetToData = table_start + FT_GET_USHORT();

    /* The documentation implies there are flags packed into the        */
    /* tuplecount, but John Jenkins says that shared points don't apply */
    /* to `cvar', and no other flags are defined.                       */

    for (i = 0; i < (tupleCount & 0xFFF); ++i)
    {
        FT_UInt tupleDataSize;
        FT_UInt tupleIndex;
        FT_Fixed apply;


        tupleDataSize = FT_GET_USHORT();
        tupleIndex = FT_GET_USHORT();

        /* There is no provision here for a global tuple coordinate section, */
        /* so John says.  There are no tuple indices, just embedded tuples.  */

        if (tupleIndex & GX_TI_EMBEDDED_TUPLE_COORD)
        {
            for (j = 0; j < blend->num_axis; ++j)
                tuple_coords[j] = FT_GET_SHORT() << 2; /* convert from        */
                                                       /* short frac to fixed */
        }
        else
        {
            /* skip this tuple; it makes no sense */

            if (tupleIndex & GX_TI_INTERMEDIATE_TUPLE)
                for (j = 0; j < 2 * blend->num_axis; ++j)
                    (void)FT_GET_SHORT();

            offsetToData += tupleDataSize;
            continue;
        }

        if (tupleIndex & GX_TI_INTERMEDIATE_TUPLE)
        {
            for (j = 0; j < blend->num_axis; ++j)
                im_start_coords[j] = FT_GET_SHORT() << 2;
            for (j = 0; j < blend->num_axis; ++j)
                im_end_coords[j] = FT_GET_SHORT() << 2;
        }

        apply = ft_var_apply_tuple(blend,
                                   (FT_UShort)tupleIndex,
                                   tuple_coords,
                                   im_start_coords,
                                   im_end_coords);
        if ( /* tuple isn't active for our blend */
            apply == 0 ||
            /* global points not allowed,           */
            /* if they aren't local, makes no sense */
            !(tupleIndex & GX_TI_PRIVATE_POINT_NUMBERS))
        {
            offsetToData += tupleDataSize;
            continue;
        }

        here = FT_Stream_FTell(stream);

        FT_Stream_SeekSet(stream, offsetToData);

        localpoints = ft_var_readpackedpoints(stream, &point_count);
        deltas = ft_var_readpackeddeltas(stream,
                                         point_count == 0 ? face->cvt_size
                                         : point_count);
        if (localpoints == NULL || deltas == NULL)
            /* failure, ignore it */;

        else if (localpoints == ALL_POINTS)
        {
            /* this means that there are deltas for every entry in cvt */
            for (j = 0; j < face->cvt_size; ++j)
                face->cvt[j] = (FT_Short)(face->cvt[j] +
                                          FT_MulFix(deltas[j], apply));
        }

        else
        {
            for (j = 0; j < point_count; ++j)
            {
                int pindex = localpoints[j];

                face->cvt[pindex] = (FT_Short)(face->cvt[pindex] +
                                               FT_MulFix(deltas[j], apply));
            }
        }

        if (localpoints != ALL_POINTS)
            FT_FREE(localpoints);
        FT_FREE(deltas);

        offsetToData += tupleDataSize;

        FT_Stream_SeekSet(stream, here);
    }

FExit:
    FT_FRAME_EXIT();

Exit:
    FT_FREE(tuple_coords);
    FT_FREE(im_start_coords);
    FT_FREE(im_end_coords);

    return error;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    TT_Vary_Get_Glyph_Deltas                                           */
/*                                                                       */
/* <Description>                                                         */
/*    Load the appropriate deltas for the current glyph.                 */
/*                                                                       */
/* <Input>                                                               */
/*    face        :: A handle to the target face object.                 */
/*                                                                       */
/*    glyph_index :: The index of the glyph being modified.              */
/*                                                                       */
/*    n_points    :: The number of the points in the glyph, including    */
/*                   phantom points.                                     */
/*                                                                       */
/* <Output>                                                              */
/*    deltas      :: The array of points to change.                      */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
FT_LOCAL_DEF(FT_Error)
TT_Vary_Get_Glyph_Deltas(TT_Face face,
                         FT_UInt glyph_index,
                         FT_Vector * *deltas,
                         FT_UInt n_points)
{
    FT_Stream stream = face->root.stream;
    FT_Memory memory = stream->memory;
    GX_Blend blend = face->blend;
    FT_Vector* delta_xy;

    FT_Error error;
    FT_ULong glyph_start;
    FT_UInt tupleCount;
    FT_ULong offsetToData;
    FT_ULong here;
    FT_UInt i, j;
    FT_Fixed* tuple_coords = NULL;
    FT_Fixed* im_start_coords = NULL;
    FT_Fixed* im_end_coords = NULL;
    FT_UInt point_count, spoint_count = 0;
    FT_UShort* sharedpoints = NULL;
    FT_UShort* localpoints = NULL;
    FT_UShort* points;
    FT_Short* deltas_x, * deltas_y;


    if (!face->doblend || blend == NULL)
        return TT_Err_Invalid_Argument;

    /* to be freed by the caller */
    if (FT_NEW_ARRAY(delta_xy, n_points))
        goto Exit;
    *deltas = delta_xy;

    if (glyph_index >= blend->gv_glyphcnt ||
        blend->glyphoffsets[glyph_index] ==
        blend->glyphoffsets[glyph_index + 1])
        return TT_Err_Ok;             /* no variation data for this glyph */

    if (FT_STREAM_SEEK(blend->glyphoffsets[glyph_index]) ||
        FT_FRAME_ENTER(blend->glyphoffsets[glyph_index + 1] -
                       blend->glyphoffsets[glyph_index]))
        goto Fail1;

    glyph_start = FT_Stream_FTell(stream);

    /* each set of glyph variation data is formatted similarly to `cvar' */
    /* (except we get shared points and global tuples)                   */

    if (FT_NEW_ARRAY(tuple_coords, blend->num_axis) ||
        FT_NEW_ARRAY(im_start_coords, blend->num_axis) ||
        FT_NEW_ARRAY(im_end_coords, blend->num_axis))
        goto Fail2;

    tupleCount = FT_GET_USHORT();
    offsetToData = glyph_start + FT_GET_USHORT();

    if (tupleCount & GX_TC_TUPLES_SHARE_POINT_NUMBERS)
    {
        here = FT_Stream_FTell(stream);

        FT_Stream_SeekSet(stream, offsetToData);

        sharedpoints = ft_var_readpackedpoints(stream, &spoint_count);
        offsetToData = FT_Stream_FTell(stream);

        FT_Stream_SeekSet(stream, here);
    }

    for (i = 0; i < (tupleCount & GX_TC_TUPLE_COUNT_MASK); ++i)
    {
        FT_UInt tupleDataSize;
        FT_UInt tupleIndex;
        FT_Fixed apply;


        tupleDataSize = FT_GET_USHORT();
        tupleIndex = FT_GET_USHORT();

        if (tupleIndex & GX_TI_EMBEDDED_TUPLE_COORD)
        {
            for (j = 0; j < blend->num_axis; ++j)
                tuple_coords[j] = FT_GET_SHORT() << 2; /* convert from        */
                                                       /* short frac to fixed */
        }
        else if ((tupleIndex & GX_TI_TUPLE_INDEX_MASK) >= blend->tuplecount)
        {
            error = TT_Err_Invalid_Table;
            goto Fail3;
        }
        else
        {
            FT_MEM_COPY(
                tuple_coords,
                &blend->tuplecoords[(tupleIndex & 0xFFF) * blend->num_axis],
                blend->num_axis * sizeof(FT_Fixed));
        }

        if (tupleIndex & GX_TI_INTERMEDIATE_TUPLE)
        {
            for (j = 0; j < blend->num_axis; ++j)
                im_start_coords[j] = FT_GET_SHORT() << 2;
            for (j = 0; j < blend->num_axis; ++j)
                im_end_coords[j] = FT_GET_SHORT() << 2;
        }

        apply = ft_var_apply_tuple(blend,
                                   (FT_UShort)tupleIndex,
                                   tuple_coords,
                                   im_start_coords,
                                   im_end_coords);

        if (apply == 0)              /* tuple isn't active for our blend */
        {
            offsetToData += tupleDataSize;
            continue;
        }

        here = FT_Stream_FTell(stream);

        if (tupleIndex & GX_TI_PRIVATE_POINT_NUMBERS)
        {
            FT_Stream_SeekSet(stream, offsetToData);

            localpoints = ft_var_readpackedpoints(stream, &point_count);
            points = localpoints;
        }
        else
        {
            points = sharedpoints;
            point_count = spoint_count;
        }

        deltas_x = ft_var_readpackeddeltas(stream,
                                           point_count == 0 ? n_points
                                           : point_count);
        deltas_y = ft_var_readpackeddeltas(stream,
                                           point_count == 0 ? n_points
                                           : point_count);

        if (points == NULL || deltas_y == NULL || deltas_x == NULL)
            ; /* failure, ignore it */

        else if (points == ALL_POINTS)
        {
            /* this means that there are deltas for every point in the glyph */
            for (j = 0; j < n_points; ++j)
            {
                delta_xy[j].x += FT_MulFix(deltas_x[j], apply);
                delta_xy[j].y += FT_MulFix(deltas_y[j], apply);
            }
        }

        else
        {
            for (j = 0; j < point_count; ++j)
            {
                delta_xy[localpoints[j]].x += FT_MulFix(deltas_x[j], apply);
                delta_xy[localpoints[j]].y += FT_MulFix(deltas_y[j], apply);
            }
        }

        if (localpoints != ALL_POINTS)
            FT_FREE(localpoints);
        FT_FREE(deltas_x);
        FT_FREE(deltas_y);

        offsetToData += tupleDataSize;

        FT_Stream_SeekSet(stream, here);
    }

Fail3:
    FT_FREE(tuple_coords);
    FT_FREE(im_start_coords);
    FT_FREE(im_end_coords);

Fail2:
    FT_FRAME_EXIT();

Fail1:
    if (error)
    {
        FT_FREE(delta_xy);
        *deltas = NULL;
    }

Exit:
    return error;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_done_blend                                                      */
/*                                                                       */
/* <Description>                                                         */
/*    Frees the blend internal data structure.                           */
/*                                                                       */
FT_LOCAL_DEF(void)
tt_done_blend(FT_Memory memory,
              GX_Blend blend)
{
    if (blend != NULL)
    {
        FT_UInt i;


        FT_FREE(blend->normalizedcoords);
        FT_FREE(blend->mmvar);

        if (blend->avar_segment != NULL)
        {
            for (i = 0; i < blend->num_axis; ++i)
                FT_FREE(blend->avar_segment[i].correspondence);
            FT_FREE(blend->avar_segment);
        }

        FT_FREE(blend->tuplecoords);
        FT_FREE(blend->glyphoffsets);
        FT_FREE(blend);
    }
}

#endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */


/* END */